Narrative:

Due to a miscom between myself and local control, I made a r-hand turn to a 270 degree heading instead of a left turn, after departing runway 13 at tmb airport. How the problem arose: due to a stuck microphone, local control was operating on a secondary frequency. When I was ready to depart runway 13, I called ready on the primary tower frequency. The stuck microphone problem was cleared up, at least sounded like it was. What happened next is where the miscom took place. The local control answered, 'come up my frequency YYY.yy (I can't remember frequency), cleared for takeoff, turn left heading 270 degrees, climb and maintain 2000 ft.' now what I heard was, 'come up my frequency XXX.xx heading 270 degrees, climb and maintain 2000 ft.' I did not hear the 'turn left' part because of the frequency change issued with my takeoff clearance. As soon as I heard the words 'come up my frequency' I moved my communication selector from 1 to 2, cutting out the words 'turn left' -- an important part of the takeoff clearance. As I was climbing out, the controller queried me about the turn and advised that in the future I need to turn the correct way for safety. I agree with the controller 100%. The scary thing is that I didn't know I was turning the wrong direction. The shortest way to 270 degrees was a right turn. The controller was pleasant about it and conditions were VFR so no harm was done. It bothered me the rest of the day because IFR changes need to be followed precisely. I was driving home thinking about what happened and why I didn't hear him say left, and then I remembered about the frequency change that was issued with my takeoff clearance. Contributing factors: a stuck microphone, frequency change issued with a takeoff clearance, my decision to change communications 1 to 2 after hearing the words 'come up my frequency.' based on my flying experience and work with controllers in the past, frequency changes are usually given by themselves, at least en route frequency changes where the words used are usually 'come up my frequency.' I'm not talking about a frequency change to the tower where departure or approach control says 'contact the tower.' this is what caused me to change communications immediately. In the future I will make sure nothing else is being said. I also strongly recommend that same controller frequency changes not be issued with important clrncs.

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Original NASA ASRS Text

Title: INSTRUCTOR PLT IN PA28-201 TURNS WRONG DIRECTION AFTER DEP ON IFR CLRNC. THERE WAS A STUCK MIKE PROB AND CTLR REQUESTED A FREQ CHANGE BUT CONTINUED WITH CLRNC. PLT CHANGED FREQ AND MISSED THE TURN PORTION OF THE CLRNC.

Narrative: DUE TO A MISCOM BTWN MYSELF AND LCL CTL, I MADE A R-HAND TURN TO A 270 DEG HDG INSTEAD OF A L TURN, AFTER DEPARTING RWY 13 AT TMB ARPT. HOW THE PROB AROSE: DUE TO A STUCK MIKE, LCL CTL WAS OPERATING ON A SECONDARY FREQ. WHEN I WAS READY TO DEPART RWY 13, I CALLED READY ON THE PRIMARY TWR FREQ. THE STUCK MIKE PROB WAS CLRED UP, AT LEAST SOUNDED LIKE IT WAS. WHAT HAPPENED NEXT IS WHERE THE MISCOM TOOK PLACE. THE LCL CTL ANSWERED, 'COME UP MY FREQ YYY.YY (I CAN'T REMEMBER FREQ), CLRED FOR TKOF, TURN L HDG 270 DEGS, CLB AND MAINTAIN 2000 FT.' NOW WHAT I HEARD WAS, 'COME UP MY FREQ XXX.XX HDG 270 DEGS, CLB AND MAINTAIN 2000 FT.' I DID NOT HEAR THE 'TURN L' PART BECAUSE OF THE FREQ CHANGE ISSUED WITH MY TKOF CLRNC. AS SOON AS I HEARD THE WORDS 'COME UP MY FREQ' I MOVED MY COM SELECTOR FROM 1 TO 2, CUTTING OUT THE WORDS 'TURN L' -- AN IMPORTANT PART OF THE TKOF CLRNC. AS I WAS CLBING OUT, THE CTLR QUERIED ME ABOUT THE TURN AND ADVISED THAT IN THE FUTURE I NEED TO TURN THE CORRECT WAY FOR SAFETY. I AGREE WITH THE CTLR 100%. THE SCARY THING IS THAT I DIDN'T KNOW I WAS TURNING THE WRONG DIRECTION. THE SHORTEST WAY TO 270 DEGS WAS A R TURN. THE CTLR WAS PLEASANT ABOUT IT AND CONDITIONS WERE VFR SO NO HARM WAS DONE. IT BOTHERED ME THE REST OF THE DAY BECAUSE IFR CHANGES NEED TO BE FOLLOWED PRECISELY. I WAS DRIVING HOME THINKING ABOUT WHAT HAPPENED AND WHY I DIDN'T HEAR HIM SAY L, AND THEN I REMEMBERED ABOUT THE FREQ CHANGE THAT WAS ISSUED WITH MY TKOF CLRNC. CONTRIBUTING FACTORS: A STUCK MIKE, FREQ CHANGE ISSUED WITH A TKOF CLRNC, MY DECISION TO CHANGE COMS 1 TO 2 AFTER HEARING THE WORDS 'COME UP MY FREQ.' BASED ON MY FLYING EXPERIENCE AND WORK WITH CTLRS IN THE PAST, FREQ CHANGES ARE USUALLY GIVEN BY THEMSELVES, AT LEAST ENRTE FREQ CHANGES WHERE THE WORDS USED ARE USUALLY 'COME UP MY FREQ.' I'M NOT TALKING ABOUT A FREQ CHANGE TO THE TWR WHERE DEP OR APCH CTL SAYS 'CONTACT THE TWR.' THIS IS WHAT CAUSED ME TO CHANGE COMS IMMEDIATELY. IN THE FUTURE I WILL MAKE SURE NOTHING ELSE IS BEING SAID. I ALSO STRONGLY RECOMMEND THAT SAME CTLR FREQ CHANGES NOT BE ISSUED WITH IMPORTANT CLRNCS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.